Rehearsals serves a purpose. Such are meant to IRON OUT issues before the REAL event, as the ENLIGHTENED in charged of Operations knows that no mortal of equipment is perfect.
During the insignificant nobody me in my formative years to serve my Nation in the Military, REHEARSALS were only normal, as our teams practice again and again, and then again, tired and presumed useless and time consuming, but eventually realized after successful missions, over every Risk Management factors, to find out critical errors, acknowledge such and IMPROVE upon such so as to ENSURE Mission Success.
It is only Hollywood movies and Armchair Morons ASS U ME, that a team can be gathered overnight, supposedly experienced in skills and equipment as they professed to be over years, that Mission success can be accomplished WITHOUT teamwork, motivation, and every factors considered in every form - personnel, training, service support, etc, etc....
Ultimately, rehearsals do serve a necessary purpose, for a REAL event, in peace or war, and MUST never be under-estimated. What that is trained, becomes INSTINCTIVE immediate reactions, to save one's and others lives.......